I'm confused too. I did not think there were regular UVB T5 bulbs. Usually T8 is referred to as regular, or non High Output. ZooMed T5s are 5.0 and 10.0, and are both High Output. Most T5 fixtures that are available are ballasted for HO, so I figured that's what you had.
Can you post the info for the exact bulb and fixture that you have?